Device for preventing clogging of drilling bits



Aug-18,1942. @.'JQ'HNSQN 7 2,293,259' l DEVICE-Fon- PREVEMIN CLOGGUG oFDRILLING BITS y Filed ual-ches, 1941 4 2 sheets-Shen 1 ai Y a mj: 20 V20a 'A' ATTORNEY.

I Aug. 1s, 1942. 5.` n. JOHNSQN' DEVICE .FOR PREVETING CLOGGING OFDRILLING BITS Filed arch 29, 1941 '2 sheets-sheet 2 ATTORNEY.

Patented Aug. 18, 19.42 i

DEVICE Fon `irtuviirrrnaa oLoGGmG oF Damme ni'rs .Clyde D. Johnson,Parkersburg, W. Va., assignor tov Acme Fishing` Tool Company,Parkersburg.

Va., a corporation of West Virginia Application March 25, 1941, serialNo. ,$135,110

. i 1 Claim.l (Cl. 255-61) The present invention relates to anapparatus` for use with rotaryl well drilling tools.

In that art, a cleansing fluid is pumped axially through the drill stemor drill pipe and the rotary drill bit so as to remove detritus loosenedby the bit, from the hole. It frequently happens in drilling that theteeth of the cutters on the bit proper become 'clogged with mud or thelike' so as to decrease the bits cutting efficiency.

The principal object of the invention, therefore, is the provision of anattachment whereby multiple streams of cleansing fluid maybe divertedfrom that passing downwardly through the drill pipe to the bit, thediverted streams passing downwardly and outwardly through theattachment, some of the diverted streams impinging upon the teeth of thecutters so as to prevent an accumulation of mud, rock or dirt at thatpoint and others of the diverted streams impinging directly upon thebottom of the hole being drilled, immediately washing away and upwardlyall loose cuttings. This prevents the bit from grinding the cuttingsover and over with resultant clogging of the bit and greatly increasedtorque on the drill pipe, that sometimes causes twist-off.

The invention further contemplates a provision for preventing a ow ofliquid with its contained detritus from arising through the axial borein the bit when the uid pumping operation is ceased, for instance duringa drill withdrawal period, or when lowering the drill pipe in the holeafter it has been withdrawn to put on a fresh bit or for other purposes.

The invention further contemplates the provii sion of a series of huidconducting passageways in the drill attachment so that regardless of thestopping position of the bit when it is screwed into the bottom of theattachment, there will be one or more passageways arranged with relationto the bit teeth so that the latter will be washedl by fluid ejectedthrough the former, and others will direct streams of uid at highvelocity' to impinge upon the bottom of the hole being drilled to washaway cuttings as they are loosened by the bit.

The invention further includes the novel combination, arrangement andconstruction of parts more fully hereinafter described and showninthedrawings, in which- Fig. 1 is a side view partly in section o f acombination involving the present invention;

Fig. 2 is a sectional view through a part of the drill string showingone'embodiment of the invention;

Fig-3 is a sectional planview along the line 3-3 0f F18. 2;`k

Fig. 4 is a sectional view Aalong line 4--4 of Fig. 2;

Fig. 5 is a plan view of the housing of the attachment with the interiorparts removed;

Fig.- 6 is a perspective view of the strainer mechanism; i

Fig. '1 is a perspective view of the valve; and

Fig. 8 is a sectional elevation showing one form of fluid conductingtube and cap.

Referring now with particularity to the ernbodiment illustrated, a drillcollar is shown at I to which a double pin sub 2 is attached in theusual manner. A body or housing 3 is attached to the sub 2 by the usualthreads, the drill bit-4 being carried in the threaded bottom portion ofthe body 3.

The housing or body 3 is provided with an axial bore in which is locateda strainer element 5 having a restricted lower portion Ii, an enlargedupper portion 1 and an intermediate perforated portion 8.

A coil spring 9 located in a. recess which sur-i rounds restrictedportion 6 of the strainer tends to push the entire strainer upwardly sothat the top of the enlarged portion 1 engages against the bottom of thesub 2.

The enlarged portion 1 of the strainer is provided with a web III4axially perforated to receive the valve stem I I.

The valve assembly includes a base plate I3,

v the rubber valve proper Il and a cap nut I5, all

held on the stem II.' A coil lspring I6 encircles the valve stem andtends to push the rubber valve part I4 against the seat I1 surroundingthe bore in the bottom of the sub.

The-lower portion of the housing 3 is provided with recesses to receivea series of `fluid conducting tubes I8 tapered as at I! so as to limittheir position within the housing. The lower end 2li of the uidconducting tubes I8 are soarranged with relation to the cutters on thedrill bit 4 that fluid ejected therethrough impinges upon the cutterteeth and/or upon the bottom of the hole as shown in Fig. 1 at 22. y

In operation, when fluid is pumped through the bore of the drill string,it depresses the spiral spring I8, opens the valve and passes into thetop of the strainer. From there it passes on each side of the web IIIcompletely through the strainer in an axial direction, and through thebore of the drill bit and performs its function in washing the detritusfrom the hole, returning to thesurface where it is recycled.

During this passage, a part of the iluid ls diverted through theperforations in the strainer and passes downwardly and outwardly throughthe iluid conducting tubes I8 to keep the cutter teeth clean and thecuttings washed from the bottom of the hole, as above mentioned.

It is to be noted that when for any reason the drill string is to heremoved from a hole, the pumping of the washing fluid is stopped. Assoonas this happens, the spring I8 closes the valve I4 tightly against theseat on the sub, thus ei'- fectively preventing the rise of iluid upthrough the center of the drill and housing. Consequently, there will beno accumulation of deposit in these parts in the interim of thenon-pumping period. As soon as the pump is again started, the valve Ilopens and the cycle is repeated. When the drill string is withdrawn fromthe hole, the weight of the fluid in the drill pipe depresses the springI 8, opening valve Il and permitting the iluid to drain out oi' the pipeas it is withdrawn. When the bit and drill pipe are run back in thehole, valve Il being closed, prevents a rise of iiuid through the drilland housing, thus avoiding accumulation of deposit in these parts andalso helping to support some of the weight of the,

drill pipe. 'I'his relieves the strain on the cables and equipment.

There are occasions when it is not desirable to have all of the iluidconducting tubes in the series open, as shown particularly in Fig. 1 andFig. 4. For instance, when it is desired to increase the pressure andvelocity of the fluid, one or more of the iluid conducting tubes can ibecapped oil' by means of cap 2| as shown in Fig. 8. Thus any number ofthe tubes may be used as desired.

From the above, it will beapparent that a de- Vice has lbeen lprovidedwhich may be readily attached to a drill string Ibetween the bit andeither the drill collar or a sub, which will not only prevent .backpressure, causing a rise o! il-uid through the drill, but will alsopermit dlverting washing fluid against the teeth o1' the cutters so asto prevent their clogging with consequent loss of elciency, and alsodivert washing fluid to the bottom of the hole at high velocity toremove cuttings as they are loosened by the bit.

The parts so provided are simple in construction, and readily assembledso that any one of them may |be replaced quickly while the drill stringis out of the hole. f

While the invention has been shown and described with particularreference to specic embodiments, it is to be understood that it is notto be limited thereto but is to be construed broadly and restrictedsolely by the scope of the appended claim.

I claim:

In combination, a drill pipe, a rotary drill bit, a housing attached tothe lower end of the drill Ipipe, said housing having fluid-conductingpassageways therein to conduct a stream of washing fluid therethroughand to discharge the same onto the outer face of the drill bit, 'saidhousing having an axial bore through which washing iluid ilows on theWay to the drill bit and the duid-conducting passageways, means to closesaid bore against back iluid pressure, a strainer element telescopicallyreceived within the axial bore in the housing, a spring pressing thestrainer element upwardly against the drill pipe, said iluidconductingpassageways in the housing receiving iluid from the exit side of thestrainer and means to close oi one of the passageways not in line withthe drill -bit after the bit has been put inplace.

CLYDE D. JOHNSON.

